What is Refractory Lining and its Importance in Operational Reliability

The refractory lining is a protective layer that is built within the furnace to protect the steel structure from high temperatures. For refractory lining, refractory bricks or monolithic refractories may be used. The chemical structure of the material being processed inside the furnace and/or the indented heat levels of the furnace determine this choice. One of the most important things to look for during the installation is the refractory lining. A professionally installed lining will extend the furnace's life and reduce energy costs. The thickness of a refractory lining is typically between 80 and 300 mm. The thickness, on the other hand, should be determined differently for each project.

The Shape of the Refractory Lining

The majority of refractory lining structures are made of fire bricks. This work can also be done with monolithic castable refractories, but fire bricks are the less expensive and simpler option. The refractory lining's brick shape varies depending on the furnace's intended use. The arch roof, for example, is the most commonly used shape. Geometries like domes and cylinders are also popular. For a long time, refractory lining is exposed to high temperatures. As a result, the lining structure is subjected to complex stress environments. As a result, all types of refractory linings require a periodic structural investigation to avoid high repair costs and ensure continuous production.

Importance of Refractory Lining in Operational Reliability

Refractory Lining, which is essentially an additional layer on the furnace, is an important factor in operational reliability. Whether the lining is new or nearing the end of its service life, any issues with refractory performance or reliability can quickly escalate into much larger potential liabilities.Keeping this in mind, metallurgical industries are more likely to use high-quality products made by the best refractory company, which can provide operational reliability with ease.

Ladle Refractory Lining

The role of the ladle is expanding as the demand for clean steel grows, as well as the advancement of ladle refining and continuous casting technology. The refractory lining of the ladle appears to be essential for its good function efficiency.Steelmaking refractory linings are used in extreme environments such as higher temperature and thermal shocks, which occur when the temperature changes unexpectedly. As molten steel is poured in from a converter or an electric arc furnace, the temperature can reach up to 1700°C. The temperature of the lining of the ladle is normally between 800°C and 1200°C before the molten steel is poured in, causing tension in the lining layer and possibly stripping of the working layer.It is widely known that high-temperature slag reactions can cause refractory material erosion. The change in the composition of slag depends mainly on the process of smelting. It is mainly related to alkaline slag in the existing smelting process, which will probably react with the brick lining.

Magnesium bricks are frequently used throughout the ladle lining.If castable refractory spinel cation for a ladle furnace is used, its damage resistance is particularly critical, as its crystalline structure helps to capture two or three-fold cations (Fe2+, etc.). Spinel-containing refractories are highly porous and have excellent mechanical properties. However, due to reduced costs, magnesium oxide materials now substitute these spinel refractories. However, it is also due to its good anti-permeability.

Blast Furnace Refractory Lining

A series of extreme physical and chemical reactions occur during the construction of a blast furnace. These reactions cause serious corrosion to refractory linings, particularly when they occur at high temperatures or during rapid temperature changes. Carbon erosion, alkali metal erosion, slag erosion, and molten iron erosion are all forms of chemical erosion. Mechanical wear is also present. These erosions happen at the same time and feed off of one another. None of the refractories has a significant advantage over the others in terms of solving the erosion problem systematically. Because of the variety and efficiency of refractory materials used in blast furnace lining, the appropriate material should be chosen for different parts due to erosion to achieve the best results.

Refractory Lining In Cement Rotary Kiln

The cement rotary kiln is one of the most significant parts of construction equipment. The consistency of the refractory lining brick, which is essential for ensuring continuous production and product calcination quality, determines the duration of its service life.

The refractory lining brick serves the following purposes in the cement rotary kiln:

• To secure the kiln barrel and avoid direct flame or airflow damage to the kiln body.
• To keep hazardous substances out of the kiln (CO, SO2).
• To prevent material and airflow from eroding the kiln body.
• Reduce kiln temperature and prevent oxidation and corrosion of the kiln body.
• To hold the heat in.
• To make the coatability better.

Conclusion

It is important to select an appropriate refractory combination based on the wear mechanism. An incorrect selection of refractories frequently results in refractory failure, which then becomes a complex problem to solve. Types of refractory lining required in a furnace by region, as well as the refractory lining trend. A good combination of high-grade refractories, combining high-efficiency cooling systems with strict furnace control to ensure high productivity without the excessive wall work, and minimizing massive 'slips' in furnaces, which can cause excessive premature damages, is needed in order to achieve the goal of long lining lives under strict operating conditions.